Spuing and method op making same



Aug, 26, 1930. w. WUERFEL Re. 17,785

SPRING AND METHOD OF MAKING SAME Original Filed Feb. 15. 192 7 gmmtov:

Reissuecl Aug. 26, 1930 UNITED STATES PATENT OFFICE WILLIAM 'WUERFEL, OFPHILADELPHIA, PENNSYLVANIA, ASSIGNOR '10 WILKENING MANUFACTURING 00., OFPHILADELPHIA, PENNSYLVANIA, A CORPORATION OF DELAWARE SPRING AND METHODOF MAKING SAME Original No. 1,668,297, dated May 1, 1928, Serial No.168,288, filed February 15,

reissue filed April 18, 1930. Serial No. 445,514.

My invention relates to a new and useful method of making springs, aswell as novel apparatus for carrying out my method, and it relates moreparticularly to a novel meth- 0d of making flat annular springs, havinga series of alternatively reversed helical formations therein each ofbut a fraction of the circumference of the spring. My invention springblanks while the latter are distorted by said series of alternatelyopposed and.

staggered axial forces.

My invention further relates to annular springs of cast iron, adapted tobe used more particularl in connection with laterally expansible pistonrings for internal combustion engines.

"With the above ends in View, my invention conslsts in formingrelatively thin annular spring blanks of cast iron and of any desiredradial width, by any suitable means, as by cutting or slicing the samefrom suitable tubular cast iron pot or cylinder of any desired wallthickness, simultaneously applying an alternate and staggered series ofaxial forces to one or a stack of such spring blanks, there-.

by to distort the same, as by clamping the same between two opposeddiscs or washers having suitable staggered projections there-.

on suitably spaced throughout the-circumference of the spring blanks,and then applying heat of sufiicient temperature to the rings, whilethus distorted until the same have set, cooling the same and lastlysplitting said rings. f

For the purpose of illustrating my invention I have, in the accompanyingdrawings,

shown a preferred form thereof, which is at present preferred by mesince it will give in practice, satisfactory and reliable results, al-

' though it is to be understood that the various instrumentalities ofwhich my inventionconsists can be variously arranged and organized 5-and' that my invention is not limited to the 1927. Application forprecise arrangement and organization of these instrumentalities asherein shown and described.

In the accompanying drawings, in which like reference charactersindicate like parts,

Figure 1 represents a front elevation of the novel apparatus adapted tocarry out my novel method, and embodying my invention.

Figure 2- represents a top plan view of the upper clamping disc.

Figure 3 Represents a top plan view of the lowerclampihg disc.

Figure 4 represents a perspective view of the finished product, madeaccording to my invention.

tive view of a cast iron pot or cylinder blank from.which the springblanks are cut.

Figure 6 represents a perspective view of a spring blank.

In carrying out my invention, I first form a series of spring blanks 1of suitable thick ness and radial width, having opposed faces 2 and 3parallel to each other and disposed in plane surfaces. The ring blanks 1arepreferably of a suitable grade of cast iron and may be formed ofuniform parallel cylindrical blanks or pots 4,0f the desired wall thick-Figure 5 represents a fragmentary perspecness, by cutting or turningtherefrom individual ring blanks 1, upon a lathe or the like,"v

along the dotted line 5 (see Figure 5).

The apparatus employed in carrying out my invention comprises chieflytwo opposed metallic discs 6-and 7 between which a stack 8 of springblanks 1 may be clamped by any suitable means, such as the bolt 9 havingits head 10 anchored in the lower disc 6, and having a nut 11 threadedonto theupper free ends thereof.

Each of the discs 6 and 7 is provided with a series of opposedprojections 12 and 13 respectively which may be formed integrallytherewith, or may be simply placed thereon in any suitable manner. Theprojections 12 and 13 are of a suitably slight height. and of anydesired contour and number, being equalhead of the bolt 9 in the lowerby suitably keying the upper disc 7 to the,

may be maintained in such relation by any suitable means, as by theanchor-a e of the 'sc 6 and ppilt'tl, by means of the sliding key 14 orthe 1 e.

The ring blanks 1 are stacked upon the lower disc 6 to any suitableheight in alignment therewith and with each other, as shown in Figures 1and 3, the upper disc 7 is then superimposed thereon, and lastly the nut11 is threaded onto the bolt 9, so as to clamp the stack of rings 8between the two discs 6 and 7. By thus clamping the stack of rings C 8between the two discs 6 and 7, having the opposed and staggeredprojections 12 and 13, on the juxta osed clamping surfaces thereof, thespring lanks 1 are simultaneous ly subjected to a series of alternate,staggered, axial forces and will thereby be uniformly distorted into thegeneral shape inclicated in Figures 1 and 4, having successive andreversed helical formations therein, over suitable fractions of thecircumference of the ring, depending on the number of projections 12 and13 employed.

The stack of spring blanks thus clamped or distorted, is then subjectedto a suitable temperature, for a suflicient length of time to permit asetting of the ring in the distorted condition or shape; The length oftime required varies. The heat may be applied to the fings by anysuitable means, such as by direct contact with a heated gas or heatedliquid, although in the preferred embodiment of my invention, I immersethe distorted rings, together with the clamping device, into a suitableliquid bath of the desired temperature, so as to obtain a more uniformheating of the rings. After a subsequent cooling of the ring, to normaltemperature, the clamping discs 6 and 7 are removed. The rings 1 willthen be in the distorted shape or condition shown in Figure 4, therebyproducing a spring indicated by the numeral 15, compressibletransversely of the flat faces 2 I and 3 thereof, that is, compressibleparallel are then split at a point 16, prefera to the axis thereof. Thecompleted springs ly at one of the several high points, that is, at theoint'of reversal of two successive helical ormations, so as to form adiscontinuous annulus which inay be s read over the piston so as to beseated wit in the ring groove thereof. v

I It will now be apparent that I have devised anew and useful method ofand apparatus for makin springs, which embodies all the features 0advantage enumerated as desirable in the statement of the invention andthe above description, and while I have, in

the present instance shown and described an embodiment thereof which isat present preferred by me, since it will give in practice satisfact'oryand reliable results, it is to be understood that such embodiment issusceptible of modification in various particulars without departingfrom the spirit or scope of the invention or sacrificing any of itsadvantages.

Having thus described my invention what I claim as new and desire tosecure "by Letters Patent is:- 1. The method of making springs of thecharacter stated which consists in first simultaneously applying aseries of distortin forces to an initially plain, parallel wallemi andcontinuous annular cast iron ring parallel to the axis thereof, so as toform successive reversed helical convolutions therein, each of afractionof the circumference of said ring,

applying heat to said ring in the distorted condition thereof, ofsufficient intensity and for a suflicient length of time to set the samein the distorted condition thereof, and lastly, severing at one point soas to break the con tinuity and to permit radial expansion thereof.

2. The method of making springs of the character stated, which consistsin first distorting an initially plain, parallel-walled and continuousannular cast iron ring parallel to the axis thereof, so as to formsuccessive reversed helical convolutions therein, each of a fraction ofthe circumference of said ring, and then applying heat to said ring inthe distorted condition thereof, of sufficient intensity and for asufficient length of time to set the same in the distorted conditionthereof, and lastly, severing at one point so as to break thecontinuityand to permit radial expansion thereof.

In testimony whereof, I have hereunto set my hand and seal this firstday of March,

its

